Ash flower gall mite

July 30, 2015

Eriophyes fraxiniflora

This cigar-shaped mite is one of a group of eriophyid mites that cause galls to form on plants. It affects only male ash trees, causing a proliferation of flower buds to form, which results in unattractive galls. Although the galls are unsightly, they aren’t harmful to the tree since they only affect the flowers. Galls start out green, then turn brown to black and persist over the winter. The size of the mite is less than 0.5 mm.

Management

No treatments are necessary, but galls may be pruned off to improve the tree’s appearance.

Ash flower gall mite
Ash flower gall affects only male flowers.

Print a PDF of this page: Ash flower gall mite

Back to IPM scouting in woody landscape plants.

Accessibility Questions:

For questions about accessibility and/or if you need additional accommodations for a specific document, please send an email to ANR Communications & Marketing at anrcommunications@anr.msu.edu.